Ideas How to use the revision cards:- Colour code the cards to show how confident you are with the topic- Ask someone at home to test you-Test yourself & highlight key words- Annotate (label) the cards- Re-write your own definitions- ‘Look, cover, check’- Draw a mind map to for some topics- Expand on key words- Read through cards-Cut out cards & stick around a room-Make a copy of/learn the key diagrams

Features of hot deserts

Hot Deserts have many different features:

- They are all dry and arid

-They may have a sandy, rocky or stony surface.

- They have very little rainfall

-They are often a lot hotter during the day, than at night (a large diurnal temperature change)

Extreme Environments

What are Hot deserts like?

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Reason 1 Distance of Travel Deserts are hot because of their proximity to the equator. Ray B has to travel further, through the atmosphere, dust & clouds,

Extreme Environments

Why are these Deserts so Hot?

Hot Deserts

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therefore not as much heat reaches the poles. Whereas Ray A has a shorter distance to travel – meaning that it retains more of the heat from the sun.

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Reason 2 Angle of Suns rays Deserts are hot because of their proximity to the equator. The earth is curved. This means that the energy from Ray B is spread/

Extreme Environments

Why are these Deserts so Hot?

Hot Deserts

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dispersed over a greater area – the energy is less intense. This is shown by ‘X’ on the picture. Whereas the energy from Ray A is concentrated on a smaller area. This is shown by ‘Y’ on the Diagram.

X

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To understand why deserts receive little rain, we first need to know why rain occurs.Rain only forms when moist air rises, cools and condenses. Often this is by:Convection current – The sun heats the earth, which heats the air above it. The air becomes less dense, rises & then condenses. E.g. Tropical Rainforests at the equator

Frontal Rain – Two air masses meet. One is less dense than the other and is forced over the top of the other one. Meaning that it rises, cools and then condenses. E.g. UK

Relief Rain. An air mass is forced over an area of high land. The air rises, cools and condenses. E.g. in Hilly areas

Extreme Environments

Why do deserts receive very little rainfall?

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Extreme Environments

Why do deserts receive very little rainfall?

Hot Deserts

In deserts, the air does not contain much moisture & the air is usually falling meaning that it cannot condense to produce rain. Reasons why air falls:Trade Winds - Due to suns heat, air rises at the equator & falls near to the tropics (Cancer/Capricorn)

Rain Shadow - Air blows across a mountain. The air then loses all of its moisture on the other sideCoastal Deserts - If the ocean is particularly cold, then the air around the coast is cooled, meaning that it will not rise & condense

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Extreme Environments

How does wind affect how dry the desert is?

Hot Deserts

The prevailing (most common) wind direction also plays a very important role in desert climates. E.g. The Prevailing wind for the

Sahara desert in Africa is from the North East. This wind blows over land, so is quite ‘dry air’ as it does not pick up moisture from the sea. The same is true for other deserts.

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Rain ShadowThe rain gets forced up and over the (windward) side of the mountain. As the air rises, it cools &

condenses. The rain falls over the mountains. By the time the clouds reach the other (leeward) side there is no moisture left in the air (e.g. Atacama desert)

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Coastal Desert -Caused by cold Currents

Which means that the air is cool and not able to rise. Sea fog can form on the coast. Some plants have adapted so they are able to use the moisture from the fog.

Cold ocean currents affect the climate of the coastal area. The colder sea cools down the land

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TRADE WINDS

forming cloud (B) and rain (C). This is why tropical Rainforests have so much rain. The air then moves away from the equator. Before it then falls. The air

Rain & clouds

The sun is most powerful at the equator. Here, the sun heats the earth (A) and the air Rises = low pressure system. As the air rises, it cools and condenses

then starts to fall at approx 300N (D) & 300S of the equator (E). As it falls, it warms up - the air can’t then produce rain = High Pressure system

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Hot deserts are depicted in a number of ways through different types of media. Accounts of historical expeditions The extremes of deserts may be stressed, & meeting different cultures. E.g. Across the empty quarter Thesiger

Through films Lawrence of Arabia, The English Patient, Flight of the Phoenix,

Historical Newspaper articles “Across the sahara by caterpillar” The Observer Jan 14th 1923, by Major Gordon Home &The Murder of Major Gordon Laing Guardian August 2nd 1828

Extreme Environments

How have people reacted to Hot Deserts (media)

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In what ways does this poem depict the desert as an extreme environment?

What poetic techniques are used?

Extreme Environments

How have people reacted to Hot Deserts (poems)

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Extreme Environments

How have people reacted to Hot Deserts (films)

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You need to know examples of different films that are set in deserts & how the depict deserts in different ways

127 hours – Adventure film about endurance in a hostile environments

The English Patient – A love story during a period of war, showing the romance of the desert desolation

Lawrence of Arabia – A film showing the importance of desert areas and group in war

Extreme Environments

How have people reacted to Hot Deserts (Historical reports)

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Historical reports:An example of the start of a report from Wilfred Thesiger.

How do historical reports such as these depict deserts?

Through TV Bear Grylls, Travel Programmes, Michael Palin (Sahara and Pole to Pole)

Through Paintings ‘Pear Blossom Highway’ Hockney. ‘St John in the desert’ Veneziano

Through Music Sometime traditional music or a ‘modern take’ on traditional themes

Each source of information will depict the desert in a different way. Sometime they will focus on the hardships of the desert and sometimes they will focus upon the difficulties. The desert may be portrayed much more positively - the mystical quality/romance of the desert may be highlighted.

Extreme Environments

How have people reacted to Hot Deserts (media)

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Paintings The use of colour and texture can be important to depict deserts in order to invoke different feelings

Extreme Environments

How have people reacted to Hot Deserts (paintings & photos)

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Photos The viewpoints and composition can be important to depict deserts in order to invoke different feelings

Extreme Environments

Where are hot deserts found?

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Names of some of the world hot deserts

When describing the distribution of hot deserts, refer to:

Distances

Compass directions

Proximity to other physical features, such as mountain, rivers, sea etc.

Hot deserts are found near to the tropic of Capricorn & Cancer & Often between 150 - 300 N & South of the Equator. This is an area of high pressure-‘air falls’ due to the Hadley cell

Extreme Environments

Where are hot deserts found?

Hot Deserts

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